INVESTIGATION OF NEW ION-CONDUCTING ORMOLYTES - STRUCTURE AND PROPERTIES

Two families of hybrid organic-inorganic composites exhibiting Li+ ion ic conduction (ORMOLYTES) have been prepared by the sol-gel process. T he first family, prepared from a mixture of 3-isocyanatopropyltriethox ysilane, 0,0' Bis (2-aminopropyl)-polyethyleneglycol (or 0,0' Bis (2-a minopropyl)-polypropyleneglycol) and lithium salt, presents chemical b onds between the organic and the inorganic phase and an ionic conducti vity sigma higher than 10(-4) S m(-1) at room temperature. Their prope rties have been related to their structure using liquid state NMR meas urements of Li-7 between -100 degrees C and +100 degrees 0 and the DMT A technique. In the-second family, prepared by ultrasonic method from a mixture of tetraethoxysilane (TEOS), polyethyleneglycol (PEG) and li thium salt, the organic and inorganic phases are not chemically bonded . Ionic conductivity a has been studied as a function of the polymer c hain length and concentration. Values of a up to 10(-2) S m(-1) at roo m temperature have been obtained (with a silica-PEG(300) system, PEG/T EOS = 40% in weight). Again, structure was investigated by liquid stat e Li-7 NMR measurements.